Vibrating mechanism for the feeding hoppers of concrete mixers, etc.



May 8, 1951 G. A. FLEISCHMANN VIBRATING MECHANISM FOR THE FEEDING HOPPERS 0F CONCRETE MIXERS,ETC. Filed July 25, 1948 2 Sheets-Sheet l INVENTOR. G'eoryefli'lczlschmanm A TTOR E) M y 5 G A. FLEISCHMANN 2,552,163

" VIBRATIN MECHANISM FOR THE FEEDING HOPPERS OF CONCRETE MIXERS,ETC.

Filed July 23, 1948 2 Sheets-Sheet 2 INVENTOR. G'eargefl i'lelsclomanm,

ATTORiEY Patented May 8, 1951 VIBRATING MECHANISM FOR THE FEEDING HOPPEES F CONCRETE MIXERS, ETC.

George A. Fleischmann, Milwaukee, Wis., as-

signor to Chain Belt Company, Milwaukee, Wis., a corporation of Wisconsin Application July 23, 1948, Serial No. 40,388

'7 Claims. 1

The invention relates to concrete mixers of the power-driven rotatable drum type, and more especially to those which are provided with a charging receptacle for receiving and transferring batches of concrete-making materials into the drum through the feeding opening thereof. Various forms of these charging receptacles have been developed and used, some of which, have been fixedly mounted on the mixer frame in juxtaposition to the feeding opening of the drum, while others have been so mounted as to be movable between a lowered position in which the materials may be the more readily introduced thereinto, and an elevated position which facilitates gravitational transfer of the batch from the receptacle into the drum.

Since the sand, gravel, crushed stone and other aggregates commonly employed in the making of concrete mixtures usually contain some moisture, there is a tendency for portions of the batch to adhere to the walls of the charging receptacle, especially where the cement is also introduced as a part of the batch, as is usually the case. Formerly it was the practice for the operator to pound on the walls of the receptacle with a hammer, mallet or other hand tool to dislodge adhering portions of the batch, but aside from the additional labor required of the operator, this has a tendency to damage the receptacle.

To relieve the operator in this respect, as well as to prevent such damage to the receptacle, it has been heretofore proposed to provide means operable automatically during batch transfer to bodily shake or vibrate the receptacle and thus prevent or overcome adherence of the batch materials to the receptacle walls; and it is the principal object of the present invention to provide improved mechanism for this purpose.

It is a further object of th-e'invention to provide a relatively simple and inexpensive mechanism of the class described, which may be supplied as an integrated unit for ready attachment to either new or old mixers with a minimum of labor and expense.

A typical example of a mixer provided with a movable charging receptacle as mentioned above, may be found in U. S. Patent No. 2,331,037 granted October 5, 1943, On an application filed by Andrew McMillan, and while the mechanism of the present invention is in no wise limited solely thereto, for purposes of disclosure said mechanism has been illustrated in the accompanying drawings, forming a part of this specification, as applied to such a mixer. In the said drawings, in which like reference characters designate like parts in all the views:

Figure 1 is a fragmentary side elevational view of the mixer, the tiltable charging hopper of which is shown as equipped with one form of hopper shaking or vibrating mechanism constructed and arranged in accordance with the invention;

Fig. 2 is an enlarged plan view of the vibrating mechanism and a portion of the hopper, partly broken away;

Fig. 3 is a longitudinal sectional view, on approximately the planes indicated by the line 3--3 in Fig. 2; and

Fig. 4 is a'detail cross sectional view, on the plane indicated by the line tl-4 of Fig. 3, looking in the direction of the arrows.

The concrete mixer here shown comprises a mixing drum H mounted in a framework I2 for rotation about a horizontal axis by means of an internal combustion engine or other source of power, not shown. The heads E3. of the drum, of which only the one at the charging end is here shown, are provided with central material-transfer openings I4, and with circumferential trackways I5 engageable with frame-carried rolls it which support and cradle the drum in the frame. An open-topped batch receiving hopper l'i, having a rear wall [8 and discharge throat it, is plyotally mounted at 29 on frame members l2 for tilting movements between the full line and broken line positions shown in Fig. 1. In the former of these positions a batch of materials in the hopper may slide by gravitational action through the hopper throat l9 and drum opening it to the interior of the drum, while in the latter position the open top of the hopper is materially lowered, thereby facilitating the deposit of a batch of materials in the hopper, all as fully explained in the aforesaid McMillan patent. The movements of the hopper between the alternate positions are accomplished through the medium of a manually operable lever 2i carried by a rockshaft 22 which is connected to the hopper by a crank arm 23 and link 2:1. The frame i2 is provided with a forwardly extending arm 25 which serves as a stop engageable by the forward wall of the hopper to limit the downward movement of the latter. I

As above indicated, the present hopper shaking mechanism is an integrated unit, and comprises a somewhat U-shaped bracket 26, one leg 2'? of which is longer than the other and is adapted to be secured to the rear wall it of the hopper if by a pair of bolts 28. The other leg 29 of said bracket carries a stud 36 upon which is journalled a roll 3|. Adjacent its lower end the bracket leg 21 carries a pair of spaced cars 32 between which one end of an angular arm 33 is pivotally mounted by a pin 34. The upper end portion of this arm is provided with a yoke-like extension 35 in which is mounted a shaft 36 on which is journalled a roller 31, preferably provided with a tire 38 of rubber or like yieldable and friction-enhancing material. The roller 31 has a laterally extending hub 39 disposed in alinement with the roll 3|, from which hub extends a spiral flange or cam ll! which, as will be clear from Fig. 4, surrounds a major portion of the hub.

The leg 21 of the bracket 26 also carries a rod 6| which extends rearwardly through an aperture 42 in the web of the arm 33 and is surrounded'by a coil spring 43 confined between the said web and a pair of lock nuts threaded .on the rod, by means of which the force exerted by the spring may be adjusted. As will be readily understood, the spring 43 constantly urges the arm 33 toward the bracket 26, and. maintains contact between the periphery of the bracket-carried follower roll 3| and the surface of the spiral cam '40 and hub 39 of roller 37.

The parts are so proportioned and arranged that when the hopper I? is moved to the batchtransfer position illustrated in full lines in Fig. 1, the arm 33 is brought into proximity to the drum head It and the roller 3'. carried by said arm is disposed in juxtaposition to the periphery of the said drum head so that the resilient tire 38 of said roller may engage with the drum-roller trackway I5. When the hopper is in this batchtransfer position, its center of gravity lies to the right (as viewed in Fig. 1.) of the hopper supporting pivot 26, thereby imparting a gravitational bias to the hopper which constantly tends to move it in a clockwise direction about said pivot, and thus the weight of the hopper and its contents will maintain engagement between the roller tire 38 and track l5.

With the drum i E rotating in a counterclockwise direction, as indicated by the arrow in Fig. 4, this contact between the tire 38 and track 15 will cause clockwise rotation of the roller 31, hub 3t and spiral cam- 49 on the shaft 36. As the said cam is thus moved beneath the follower roll 3! it lifts the latter, and through the bracket 26 acts to swing the hopper about its pivot 20, slightly away from the drum. This movement of the hopper also separates it somewhat from the arm 3, against the action of spring @3. When the end of the spiral cam 43 moves from beneath the roll 3|, as shown in Fig. l, the clockwise gravitational bias of the hopper, aided by the action of the spring :23, returns the hopper rapidly and causes the roll St to contact hub 39 with a jolt which serves to dislodge any of the concrete materials tending to adhere to the hopper walls.

While it is preferred to employ the spring 53 in the construction as above set forth, its use is not absolutely essential in cases where, as here, the hopper is otherwise biased toward the drum when in the transfer position. In the arrangement shown and above described, the primary function of the spring is to maintain yielding engagement between the cam to and follower 3 I, and its action in aiding the snapping back of the hopper is supplemental to the gravitational bias of the hopper. Should the spring be omitted the mechanism still will function by reason of said hopper bias; but in such case the rod 4| and nuts 44 (or some equivalent stop device) should be present to limit separation of the arm 33 and hopper H when the latter is moved to its batch-receiving position, whereby to insure proper positioning of the arm for engagement of roller tire 38 with the track l5 when the hopper is returned to the transfer position.

Although the drum II normally rotates rather slowly, because of the marked difference in the diameters of the drum track I5 and the roller tire 38, the roller and its cam 40 will be rotated much faster, with consequent relatively rapid shaking or jolting of the hopper whenever it is in its transfer position. Being carried by the hopper, the shaping mechanism of course will be rendered inoperative whenever the hopper is moved to the broken line batch-receiving position shown in Fig. l, but will automatically become operative again with return of the hopper to transfer position.

It will be noted that the present device is an integrated unit which may be sold as such for application to mixers already in use; or it may be readily applied to new machines. In either case no change in the mixer structure is necessary, beyond the drilling of two holes in the hopper wall for reception'of the attaching bolts 28.

What is claimed is:

1. In a concrete mixer comprising a frame, a mixing drum rotatably mounted thereon, and a vibratably mounted hopper for charging materials into said drum; an arm mounted on and supported by the hopper for relative movements between the two; a cam member carried by said arm and having a driving portion engageable with the drum for movement thereby; a follower element carried by the hopper and engageable with said cam, whereby movement of the latter may produce movements of the hopper relative to the arm and drum; and means controlling relative movement between the arm and hopper.

2. In a concrete mixer comprising a frame, a mixing drum rotatably mounted thereon, and a vibratably mounted hopper for charging materials into the drum; an arm pivotally carried by the hopper for relative movement between the two; a cam journalled on said arm and having a driving member engageable with the drum for rotation thereby; a follower element carried by the hopper and engageable with said cam, whereby rotation of the latter by the drum may produce vibratory movements of the hopper relative to the arm; and resilient connections between the arm and hopper controlling relative movement between them and maintaining contact between the cam and follower element.

3. In a concrete mixer comprising a frame, a mixing drum rotatably mounted thereon, and a hopper for charging materials into said drum mounted for bodily movements to and from a batch-transferring position relative to the drum; an arm mounted on and supported by the hopper for relative movement between the two; a rotatable cam carried by said arm and having a driving member engageable with the drum when the hopper is in said transfer position, whereby to rotate the cam; a follower element carried by the hopper and engageable with said cam, whereby rotation of the latter may produce vibratory movements of the hopper relative to the arm; and means for substantially maintaining the relationship of the arm to the hopper when the latter is moved away from its said transfer position, comprising motion limiting connections between the two.

4. In a concrete mixer comprising a frame provided with drum-supporting rollers, a mixing drum having a circumferential trackway engageable with said rollers to rotatably mount the drum thereon, and a hopper for charging materials into said drum, mounted for swinging movements to and from a batch-transferring position relative to the drum; an arm pivotally mounted on the hopper adjacent the drum; a rotatable cam carried by said arm and having a driving member engageable with said drum trackway when the hopper is in said transfer position, whereby the drum may rotate said cam; a follower element carried by the hopper and engageable with the cam, whereby rotation of the latter may produce vibratory movements of the hopper relative to the arm and drum; and resilient connections between the arm and hopper for maintaining contact between the cam and follower element, and also maintaining proper relationship between the arm and hopper, when the latter is moved away from its transfer position, to insure re-engagement of the cam driving member with the drum trackway upon return of the hopper to said position.

5. A unit for vibrating a movable feeding hopper of a rotatable drum concrete mixer, comprising a bracket member adapted to be secured to the hopper; an arm mounted on said bracket for relative movement between the two, and disposable in proximity to the mixer drum; a cam carried by said arm, having a driving member engageable with the drum for movement thereby; a cam follower carried by the bracket and engaging said cam, whereby movement of the latter may produce vibratory motion of the bracket and hopper relative to the arm; and connections between the arm and bracket for maintaining contact between the cam and follower.

6. An integrated unit for attachment to a movable feed hopper of a rotatable drum concrete mixer, whereby to shake said hopper during the transfer of materials therefrom into the drum, said unit comprising a bracket member having a portion for ready attachment to a wall of the hopper; an arm pivotallyearried by said bracket for disposal in proximity to the drum; a rotatable cam journalled on the arm and having a driving roller disposed for engagement with the drum for rotation thereby; a cam follower mounted on the bracket and engageable with said cam, whereby rotation of the latter may produce vibratory motion of the bracket and hopper relative to the arm; and resilient connections between the bracket and arm for maintaining yieldable engagement between the cam and follower.

7. An integrated unit for attachment to a movable feed hopper of a rotatable drum concrete mixer, whereby to shake said hopper during transfer of materials therefrom into the drum, said unit comprising an angular bracket member having a pair of spaced legs, one of which is attachable to a wall of the hopper; an arm pivotally carried by such leg for relative movement between the two, said arm having a portion disposable in proximity to the periphery of the drum; a cam journalled on said arm portion and having a driving roller engageable with said drum periphery for rotation thereby; acam follower mounted on the other leg of said bracket and engageable with said cam, whereby rotation of the latter may produce vibratory movements of the bracket and hopper relative to the arm; and spring connections between the arm and bracket yieldably controlling the movements between them and maintaining contact between the cam and follower.

GEORGE A. FLEISCHMANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,996,209 Lichtenberg Apr. 2, 1935 2,276,125 Viall Mar. 10, 1942 

